Under the guidance of Dr Julius Axelrod, Dr Hampson is examining the physiological role of cannabinoid receptors in the brain. He has discovered that marijuana derived cannabinoids possessantioxidant properties. During the last year he has continued both the original project and exploited his novel finding. In collaboration with Dr. Grimaldi, he examined the physiological role of cannabinoid receptors in preventing ischemia. He also found cannabidiol (CBD), a non- psychoactive cannabinoid, to be a selective inhibitor of lipoxygenase enzymes. In particular, he has demonstrated that CBD is a potent inhibitor of the inflammatory 5-lipoxygenase although it does not inhibit 12-lipoxygenase. The product of 12-lipoxygenase can protect neurons from toxic insult. It was already known that 12-lipoxygenase products are formed during a stroke and CBD was already under examination as a neuroprotective antioxidant. However the newfinding that CBD is a selective lipoxygenase inhibitor, suggests that during a stroke, CBD may both increase formation of protective compounds and block formation of inflammatory agents. In addition, in collaboration with Dr Eskay (NIAAA), Dr Hampson has demonstrated that CBD significantly reduces the damaging effects of alcohol on the brain. Together with Dr Zimmer (NIMH), Dr Hampson is examining whether CBD can increase the analgetic effects of morphine while lowering the required dose.Results indicate that CBD increases morphine analgesia by 50- 300%.In collaboration with Dr Rosenthal (GWU), CBD is being studied in a dog model of cardiac arrest - induced cerebral ischemia. - cannabinoid, cannabidiol, ischemia, marijuana, free radicals, antioxidants, glutamate